DIY F2 clone

[Scott Valley]

I am new to this forum, so apologies if the answer to this question has been worn out, but I am interested in building an F2 clone. Dick Olsher is mandating use of the F2 to power the Eminence woofer in his Basszilla speaker and I can't afford the store-bought version.

Has the Reverend Pass released the necessary circuit information to now make a DIY clone possible? If so, where does one find it? If not, is there some timetable?

[lineup]

First Watt is a "kitchen-table" effort by Nelson Pass. First Watt builds very simple high quality, low power audio amplifiers intended for use with sensitive loudspeaker drivers.

These amplifiers are hand-built by Pass and are available in very limited quantities. Each design is a different exploration into high quality at low power.
At the end of the sales cycle of new product, the schematics and technical details of each design will be posted for the benefit of the "DIY" community.

As you can see from this quote of FAQ at http://www.firstwatt.com/faq.htm
the promise we can trust in is:
... there will be, in time technical details of each design
... but not until The End of sales cycle of new product.

As what I can understand, Nelson may correct me, this means details are public for F1 now.
As F2 is now a new product, for sale. Like is F3.
And we have to wait patiently some time for more detailed info of F2 and F3.

Or sign up for to be a lucky buyer of an exemplar of F2!


What we can download now, by the generosity of Mr. Pass is at this download page:
http://www.firstwatt.com/downloads.htm

Manuals:
F1 Owner's Manual
F2 Owner's Manual
F3 Owner's Manual
Aleph J Owner's Manual

F1 Service Manual

F1 Review by Jon Ver Halen of Lowther American.

Articles:
Current Source Crossover Filters
Current Source Amplifiers and Sensitive / Full-Range Drivers
.

For details of an amplifier we look for Service Manual
as for service there would mostly be a schematic needed.


regards
lineup

[steenoe]

Hi Scott, welcome to the Pass forum Yep we backengineered the F2. Mr. Pass said it was pretty close to the factory amp.
The development is mainly in this thread:
zen without feedback
And this thread contains loads of good information and some examples of finished amps.
F2 Initial Listening Impressions
Apassgear and I worked together on a boardlayout that is confirmed functional.
Good luck and happy building

Steen

[Nelson Pass]

Tomorrow

[steenoe]

Tomorrow

Wow, that sounds great. Man, have I been waiting for this

Steen

[Scott Valley]

Delighted to learn that some folks have already been developing F2 clones. And the "tomorrow" announcement from Mr. Pass about official circuit availability, while suitably cryptic to afford him the necessary wiggle room (been there, done that), is gratifying.

Seeing as what little skill I have is in speaker building and wiring up tube amps, I'm going to need all the help I can get to assemble an F2 clone. The operative word here is "assemble," as there's no way in hell I could actually build one from a schematic. So for those who are planning to whip together clone F2 circuit boards, power supplies, heat sinks et al, I hope you can be persuaded (with suitable incentives) to make extras enabling the electronics impaired to assemble something that won't turn into molten aluminum when switched on.

Here's hoping tomorrow arrives soon...

[Nelson Pass]

Here we go

[Netlist]

Now, this is nice.
We get it faster than the official Firstwatt site.

Is there a particular reason to do the series/parallel resistor bank instead of one or two resistors?

/Hugo

[Nelson Pass]

I use 3 watt resistors, and the lowest value I have in stock
are .33 (now used up) and the .47 ohm from Panasonic, which
is their lowest value. So parallel/series resistors are examples
where I want a lower value than .47 or more dissipation than
a watt or so.

[Netlist]

Thanks,
I think I'll try this exercise in simplicity one day on my Fonkens. (FE127E)

/Hugo